/* wf_pow.c -- float version of w_pow.c.
 * Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com.
 */

/*
 * ====================================================
 * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
 *
 * Developed at SunPro, a Sun Microsystems, Inc. business.
 * Permission to use, copy, modify, and distribute this
 * software is freely granted, provided that this notice
 * is preserved.
 * ====================================================
 */

/*
 * wrapper powf(x,y) return x**y
 */

#include "fdlibm.h"
#include <errno.h>

#ifdef __STDC__
    float powf(float x, float y)    /* wrapper powf */
#else
    float powf(x,y)         /* wrapper powf */
    float x,y;
#endif
{
#ifdef _IEEE_LIBM
    return  __ieee754_powf(x,y);
#else
    float z;
    struct exception exc;
    z=__ieee754_powf(x,y);
    if(_LIB_VERSION == _IEEE_|| isnan(y)) return z;
    if(isnan(x)) {
        if(y==(float)0.0) {
        /* powf(NaN,0.0) */
        /* error only if _LIB_VERSION == _SVID_ & _XOPEN_ */
        exc.type = DOMAIN;
        exc.name = "powf";
        exc.err = 0;
        exc.arg1 = (double)x;
        exc.arg2 = (double)y;
        exc.retval = 1.0;
        if (_LIB_VERSION == _IEEE_ ||
            _LIB_VERSION == _POSIX_) exc.retval = 1.0;
        else if (!matherr(&exc)) {
            Djy_SaveLastError(EDOM);
        }
            if (exc.err != 0)
               Djy_SaveLastError(exc.err);
                return (float)exc.retval;
        } else
        return z;
    }
    if(x==(float)0.0){
        if(y==(float)0.0) {
        /* powf(0.0,0.0) */
        /* error only if _LIB_VERSION == _SVID_ */
        exc.type = DOMAIN;
        exc.name = "powf";
        exc.err = 0;
        exc.arg1 = (double)x;
        exc.arg2 = (double)y;
        exc.retval = 0.0;
        if (_LIB_VERSION != _SVID_) exc.retval = 1.0;
        else if (!matherr(&exc)) {
            Djy_SaveLastError(EDOM);
        }
            if (exc.err != 0)
               Djy_SaveLastError(exc.err);
                return (float)exc.retval;
        }
        if(finitef(y)&&y<(float)0.0) {
        /* 0**neg */
        exc.type = DOMAIN;
        exc.name = "powf";
        exc.err = 0;
        exc.arg1 = (double)x;
        exc.arg2 = (double)y;
        if (_LIB_VERSION == _SVID_)
          exc.retval = 0.0;
        else
          exc.retval = -HUGE_VAL;
        if (_LIB_VERSION == _POSIX_)
          Djy_SaveLastError(EDOM);
        else if (!matherr(&exc)) {
          Djy_SaveLastError(EDOM);
        }
            if (exc.err != 0)
               Djy_SaveLastError(exc.err);
                return (float)exc.retval;
            }
        return z;
    }
    if(!finitef(z)) {
        if(finitef(x)&&finitef(y)) {
            if(isnan(z)) {
            /* neg**non-integral */
            exc.type = DOMAIN;
            exc.name = "powf";
            exc.err = 0;
            exc.arg1 = (double)x;
            exc.arg2 = (double)y;
            if (_LIB_VERSION == _SVID_)
                exc.retval = 0.0;
            else
                exc.retval = 0.0/0.0;   /* X/Open allow NaN */
            if (_LIB_VERSION == _POSIX_)
                Djy_SaveLastError(EDOM);
            else if (!matherr(&exc)) {
                Djy_SaveLastError(EDOM);
            }
                if (exc.err != 0)
                    Djy_SaveLastError(exc.err);
                    return (float)exc.retval;
            } else {
            /* powf(x,y) overflow */
            exc.type = OVERFLOW;
            exc.name = "powf";
            exc.err = 0;
            exc.arg1 = (double)x;
            exc.arg2 = (double)y;
            if (_LIB_VERSION == _SVID_) {
               exc.retval = HUGE;
               y *= 0.5;
               if(x<0.0&&rint(y)!=y) exc.retval = -HUGE;
            } else {
               exc.retval = HUGE_VAL;
                       y *= 0.5;
               if(x<0.0&&rint(y)!=y) exc.retval = -HUGE_VAL;
            }
            if (_LIB_VERSION == _POSIX_)
                Djy_SaveLastError(ERANGE);
            else if (!matherr(&exc)) {
            Djy_SaveLastError(ERANGE);
            }
                if (exc.err != 0)
                    Djy_SaveLastError(exc.err);
                    return (float)exc.retval;
                }
        }
    }
    if(z==(float)0.0&&finitef(x)&&finitef(y)) {
        /* powf(x,y) underflow */
        exc.type = UNDERFLOW;
        exc.name = "powf";
        exc.err = 0;
        exc.arg1 = (double)x;
        exc.arg2 = (double)y;
        exc.retval =  0.0;
        if (_LIB_VERSION == _POSIX_)
            Djy_SaveLastError(ERANGE);
        else if (!matherr(&exc)) {
            Djy_SaveLastError(ERANGE);
        }
        if (exc.err != 0)
            Djy_SaveLastError(exc.err);
            return (float)exc.retval;
        }
    return z;
#endif
}

#ifdef _DOUBLE_IS_32BITS

#ifdef __STDC__
    double pow(double x, double y)
#else
    double pow(x,y)
    double x,y;
#endif
{
    return (double) powf((float) x, (float) y);
}

#endif /* defined(_DOUBLE_IS_32BITS) */
